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  <title>Document</title>
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<body>
  <p id="content"> 请等三秒钟!</p>
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<script>
  setTimeout("changeState()",5000 );  
function changeState(){  
	let content=document.getElementById('content');  
	content.innerHTML="<div style='color:red'>我是三秒后显示的内容！</div>";  
}
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